Electrophotographic recording apparatus for a facsimile device

ABSTRACT

An electrophotographic recording apparatus for a facsimile device in which an exposure unit and a developing unit are disposed on the opposite sides of a photosensitive body to thereby perform simultaneous exposure and development at the same position. The respective processes of the electrophotographic recording operation, i.e., exposure, development and transfer processes, rotation of the photosensitive body, and paper conveyance are performed synchronously with the timing at which image data for each line is received.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to electrophotographic recording apparatus forfacsimile devices which are capable of recording received image datawith high quality without using an image data memory such as a pagememory.

2. Description of the Prior Art

Carlson's process is typical of electrophotographic recording systemsusing toner. .This process includes charging, exposure, development,transfer, cleaning and erasing steps performed sequentially separatelyand the respective components of the system used are disposeddispersively around a photosensitive body.

FIG. 6 shows time changes in the surface potential of the photosensitivebody from charging to exposure in Carlson's process. As shown in FIG. 6,the surface potential V caused by a charger attenuates with time, whichis hereinafter referred to as a dark attenuation. Only that portion of aphotosemiconductor layer of the photosensitive body exposed by lightirradiation means becomes conductive and electrons become freely movabletherein and thus the potential at the surface of that portion irradiatedwith light rapidly decreases. At the exposure step, an electrostaticlatent image is formed on the photosensitive body surface as thedifference between the quantity of electric charges in the areas wherelight strikes and the quantity of electric charges in the areas wherelight does not strike. The dark attenuation rate is, for example, about20% in 5 seconds. The potential of electrostatic charges formed on thephotosensitive body depends greatly on the time required for thecharging and the time taken from the end of the charging to the start ofthe exposure. Therefore, in order to provide a high quality imagewithout uneven density while maintaining the surface potential constant,it is necessary to maintain constant the time taken from the charging tothe development.

The following problems arise in the use, in a facsimile device, of anelectrophotographic recording apparatus according to Carlson's processand having the above qualities. Most of facsimile devices employ aredundency reduction encoding system which compresses and transmitsimage data in each line in accordance with the degree of succession ofwhite pixels and dark pixels in order to shorten the transmission timeand the length of data contained in each line differs from that in adifferent line.

Therefore, the time required for decoding at the receiver end variesfrom line to line. Thus, when such image data is converted to an opticalsignal at the exposure unit without storing such data in memory, thetime taken from the charging to the end of the exposure varies line toline and as a result the attenuation of the surface potential at thephotosensitive body due to dark attenuation varies from line to line,the quantity of toner deposited at the subsequent exposing step variesfrom line to line to thereby produce variegated density distribution.

Therefore, if an electrophotographic recording apparatus using Carlson'sprocess is applied in a facsimile device, a memory having a capacitylarge enough to store at least one page of image data must be provided,the image data stored in the memory is delivered to the exposure meansat constant timing, the time intervals taken for charging, developmentand transfer of data in all the lines must be equal. The provision ofthe memory increases the whole system cost.

In contrast with the recording apparatus using Carlson's process,Published Examined Japanese Patent application No. 59592/1985 disclosesa recording apparatus in which a photosensitive body includes athree-layered structure which comprises a transparent support layer, atransparent conductive layer and a photosemiconductor layer. An exposuredevice and a developing unit are disposed inside and outside,respectively, of the photosensitive body in opposing relationship suchthat simultaneously with light irradiation from the inside of thephotosensitive body, toner is fed from the outside of the photosensitivebody, which removes the use of a charger. According to this techniques,charges are produced at that portion of the photosensitive bodyirradiated with light, and toner having a polarity opposite to that ofthe charges is deposited on that portion to form a toner image.

According to this technique, an electrostatic image is formed anddeveloped at a single position around the photosensitive body, so thatthe image is not influenced by dark attenuation, which is prospective asthe electrophotographic recording system used in a facsimile device.

SUMMARY OF THE INVENTION

It is an object of this invention to provide an electrophotographicrecording apparatus for a facsimile device which positively uses thetechnique of the above Published application No. 59592/1985, and addes,to the structure of the Application, means for altering the processingtime intervals for the respective lines to thereby form a high qualityimage without uneven density without using an image data memory such asa page memory.

This invention provides an electrophotographic recording apparatus for afacsimile device comprising:

a photosensitive body including a transparent conductive layer and aphotosemiconductor layer layered in this order on a transparent support;

exposure means having a plurality of light emitting elements disposed ina row and positioned on the transparent support side of thephotosensitive body for converting input image data for one line to anoptical signal, irradiating the transparent support of thephotosensitive body with the converted light signal to form on thephotosemiconductor an electrostatic latent image corresponding to theimage data;

development means disposed on the opposite side of the photosensitivebody from the exposure means for depositing toner having a polarityopposite to that of the electrostatic latent image on the latent imagein the photosemiconductor layer by application of a predetermined biasvoltage to a developing electrode;

transfer means for transferring the toner deposited on thephotosemiconductor layer to a recording medium;

means for conveying the recording medium between the transfer means andthe photosemiconductor layer;

means for rotating the photosensitive body; and

control means for operating the exposure means, the development means,the conveying means and the rotating means synchronously with thereceipt timing of received image data for each line and synchronizingthe light irradiation timing of the exposure means, the timing ofapplication of a bias voltage for one line in the development means, thestart timing of the conveyance of the recording medium for each line andthe start timing of the rotation of the photosensitive body for eachline with the receipt timing of the received image data for each line.

According to such inventive structure, exposure and development areperformed simultaneously at the same position, and exposure,development, paper feed and rotation of the photosensitive body areperformed synchronously with the receipt timing of image data in eachline, so that the recording speed in the subscanning direction is variedin accordance with the length of image data in each line.

Therefore, according to this invention, a page memory for storingreceived image data is not required and the cost of the whole facsimiledevice is reduced. Since a dark attenuation in the photoconductor layeris eliminated, uneven density due to the dark attenuation is notproduced to thereby to provide a uniform quality facsimile image.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 conceptually shows the photosensitive body and other elementsassociated therewith.

FIG. 2 is a block diagram showing an illustrative structure of a controlsystem in one embodiment of this invention.

FIGS. 3a-3f is a timing chart showing the control operation of acontroller.

FIG. 4 is a cross section view of a photosensitive body used in theembodiment.

FIGS. 5a-5d is an operation chart explaining the principle ofelectrophotographic recording used in the embodiment.

FIG. 6 is a timing chart showing the aspect of a dark attenuation.

DESCRIPTION OF THE PREFERRED EMBODIMENT

This invention will now be described in detail with reference to anembodiment thereof shown in the accompanying drawings.

FIG. 1 shows a photosensitive body and other elements associatedtherewith in the embodiment of this invention. Also shown in FIG. 4, thephotosensitive body 4 has a three-layered structure which comprises atransparent conductive layer 2 and a photosemiconductor layer 1superposed in this order on a transparent support body 3. Thetransparent conductive layer 2 is grounded.

Disposed within the photosensitive body 4 are an optical write head 5which comprises an array of light emitting diodes for one line whichconverts received electrical image data signal to an optical signal, andan array of self-collecting type lenses 6 which guides the light fromthe head 5 to the transparent support 3 to form on thephotosemiconductor layer 1 an erect image having an equal magnificationas viewed from the inside. These elements constitute an exposure means7.

Disposed outside the photosensitive body 4 is a magnetic brushdeveloping unit 8 such that the developing position is opposite to aposition where light irradiation by the exposure means 7 is performed.The magnetic brush developing unit 8 includes a fixed permanent magnetshaft 9 and a concentric sleeve 10 provided rotatable on the shaft 9.Magnetic toner 13 is drawn and deposited magnetically on the outersurface of the sleeve 10. Furthermore, a power source 15 which suppliesa voltage across the sleeve 10 and the transparent conductive layer 2 ofthe photosensitive body 4 such that the sleeve is negative in potentialrelative to the conductive layer, a switch 14, a hopper 11, and a tonerregulating plate 12 are provided. The magnetic toner 13 is a mixture offine resin powder and iron powder called a carrier.

A transfer unit 20 is provided under the photosensitive body 4. Avoltage is applied across a metal wire 24 and the transparent conductivelayer 2 via a switch 21 for a power source 22 such that the metal wire24 is positive in potential relative to the layer 2.

Recording paper 19 is carried by a drive roller 17 and a feed roller 18via a guide plate 25 between the transfer unit 20 and the photosensitivebody 4. The paper is then discharged via a fixing device (not shown).The drive roller 17 is rotated by a pulse motor 16 which also drives thephotosensitive body 4 and sleeve 10. Appropriate gear wheels areprovided between these elements and the pulse motor 16 to therebycoordinate the rotational speeds of the elements.

Also provided within the photosensitive body 4 is a light source 60which initializes the charging state of the photosemiconductor layer 1by light irradiation therefrom.

The principles of exposure, development and transfer processes performedby this apparatus will now be described in accordance with the processsteps shown in FIGS. 5(a)-(d). When a part of the photosemiconductorlayer 1 of the photosensitive body 4 is irradiated with light, thatirradiated portion alone becomes conductive while other nonirradiatedportions remain nonconductive. Therefore, if the switch 14 of thedeveloping unit 8 is turned on synchronously with light irradiation forone line by the light irradiation means 7, the potential of the sleeve10 becomes negative relative to that of the transparent conductive layer2, so that positive charges appear in the irradiated portion of thephotosemiconductor layer 1.

As described above, the toner mixture 36 is composed of carrier andtoner powder. As the sleeve 10 rotates, the carrier and toner powdercause friction, so that the toner 13 is beforehand charged negatively.Therefore, the negatively charged toner 13 is drawn against anddeposited on the surface of the photosemiconductor layer 1 by turning onthe switch 14, as shown in FIG. 5(a).

The switch 14 is maintained turned on for a predetermined time and thenturned off until the developing operation for the next line isperformed. FIG. 5(b) shows the state of the toner during the offinterval. When the switch 14 is turned off, the positive charges in thetransparent conductive layer 2 flow to ground. Since the toner at thatportion of the conductive layer not irradiated with light is no longerdrawn electrostatically onto the surface of the photosensitive body 4,it is drawn to the sleeve 10 by the magnetic force of the permanentmagnet shaft 9. Thus toner 13 is deposited only on the irradiatedsurface portion of the photosensitive body 4.

In the transfer process, as shown in FIG. 5(c), the switch 21 is turnedon to apply a voltage across the transfer unit 20 and the transparentconductive layer 2 such that same is positive in potential relative tothe transfer unit 20 to thereby render the back of the recording paper19 positive in potential. Thus negatively charged toner 13 is drawn tothe paper 19 surface by Coulomb force. Negative charges appear on thephotosemiconductor layer side surface of the transparent conductivelayer 2 and react with negative toner 13 to cause a repulsion force tothereby ensure more reliable deposition of the toner 13 onto the paper19. When the transfer operation ends, the switch 21 is turned off asshown in FIG. 5(d) until the transfer of the next line starts. In orderto eliminate the remaining charges in the photosemiconductor layer 1,the inside of the photosensitive body 4 is irradiated with light by thelight source 60, as shown in FIG. 5(d), to become conductive so that thecharges on the photosemiconductor layer 1 escape to the ground tothereby initialize the charge state of the photosemiconductor layer 1.By repetition of the above operation for each line, a toner imagecorresponding to the electrostatic latent image on the photosensitivebody is formed on the paper 19.

FIG. 2 shows the illustrative structure of a control system of thereceipt end obtained when the electrophotographic recording apparatus isprovided in the facsimile device.

Like a conventional facsimile receiver, the facsimile device includes anetwork control unit 30 which controls switching between the facsimiletelephone lines, a demodulator 31 which demodulates the received signal,a decoder 32 which decodes the received image data. The decoded imagedata is input to a line memory 33 which includes two line buffers whichare used such that image data is input to one line buffer while secondimage data is read out from the other line buffer in an alternatelyswitched manner.

The image data output by the line memory 33 is input to a head drivecircuit 34 which includes a plurality of shift registers corresponding,for example, to the light emitting diodes of the optical write head 5.The light emitting diodes are turned on and off in accordance with theinput image data to form an electrostatic latent image corresponding tothe image data for each line on the photosemiconductor layer 1 of thephotosensitive body 4. The start timing and time duration of theoperation of the head drive circuit 34 for each line is controlled by acontrol signal HS from a controller 40.

The controller 40 also controls the operation start timing and timeduration of the operation of a motor drive circuit 35 and switches 14and 21 for each line using signals MS, SS and TS. The controller 40further controls the network control unit 30, and a demodulator 31 andthe decoder 32 and switching between the line buffers 33.

The timing control of the circuits 34, 35, 14 and 21 using thecontroller 40 will now be described using the timing chart of FIG. 3.The controller 40 detects a signal EOL (End Of Line) contained in thereceived image data, thereby detecting when the end of the data in eachline appears. Synchronously with the EOL signal (FIG. 3(a)), the timingcontrol of the respective circuit 34, 35, 14 and 21 is performed.

It takes a predetermined delay time from the inputting of the image datato the decoder unit 32 through the processing of the data by thedemodulator 32 to the inputting of the resulting data via the linebuffer 33 to the head drive circuit 34. When the controller 40 detectsan EOL signal intervening between adjacent data items in each line, itdelays the EOL signals in the line by the predetermined times to formEOL' signals (FIG. 3(a)). EOL' signals are EOL signals which aredistributed at uneven intervals in each line and delayed by thepredetermined times.

The controller 40 performs exposure by the light irradiation means 7,development by the developing unit 8, rotation of the photosensitivebody 4, and the conveyance of recording paper synchronously with theformed EOL' signals.

When the first EOL' signal is produced, the image data in the first linehas been inputted to the head driver 34 and the controller 40 changesthe signals HS and SS to "1" when the first EOL' is produced (FIGS.3(a), (b), (c). This causes the optical write head 5 to be driven inaccordance with the first line image data to thereby form anelectrostatic latent image corresponding to the first line image data onthe photosensitive body 4, as shown in FIG. 5(a), and to deposit toneron that portion of photosensitive body 4 corresponding to the firstline. The signals HS and SS fall to "0" when a set predetermined timehas past.

The controller 40 inputs a predetermined number of pulse signals MS tothe motor driver 35 synchronously with the fall of the signal SS torotate the pulse motor 16 through a predetermined angle. The pulse motor16 is connected via gear wheels to the rotational shaft of thephotosensitive body 4, the rotational shaft of sleeve 10, and the driveroller 17, so that the photosensitive body 4 and the sleeve 10 arerotated via corresponding predetermined angles in the directions a and b(FIG. l) in accordance with the rotation of the pulse motor 16 andstopped (FIG. 3(d)). Recording paper 19 is conveyed through apredetermined distance from a predetermined standby position Pl (FIG. 1)in accordance with the rotation of the drive roller 17 (FIG. 3(e)). Whenthe signal SS falls to "0", the switch 14 is turned off and, as aresult, toner is deposited only on that portion of the body irradiatedwith light, as shown in FIG. 5(b).

When a second EOL' signal is generated, the controller 40 changes thesignals SS and HS to "1" simultaneously with the generation of the EOL'signal, as mentioned above, to turn on the switch 14 and drive the headdriver 34. When the second EOL' signal is generated, the image data forthe second line has already been inputted to the head driver 34 and thustoner is deposited on that portion of the photosensitive body 4corresponding to the second line. The controller 40 maintains thesignals SS and HS at "1" for a predetermined time and then changes themto "0". Simultaneously with the signals SS falling, the controller 40outputs a predetermined number of pulse signals MS. Thus toner isdeposited only on that portion of the photosensitive body 4corresponding to the second line and irradiated with light. Thephotosensitive body 4 and sleeve 10 are rotated by correspondingpredetermined angles by the rotation of the pulse motor 16 in accordancewith the pulse signals MS to thereby convey the recording paper 19through a predetermined distance.

In this way, the controller 40 repeats transmission of signals HS, SSand MS synchronously with the scanning line synchronous signal EOL' forcontrol purposes. According to this control operation, the width of onepulse of the signal HS, as taken as an example, is the same for all therespective lines and the standby time interval from the fall of a pulseto the rise of the next pulse differs for each different line. As aresult, in the case of exposure operation using the signal HS, the lightirradiation time interval for one line is the same for all the lineswhile the time interval from the end of exposure for a line to the startof exposure for the next line exposure differs from that for a differentline in accordance with a signal EOL. This applies to the rotation ofthe photosensitive body 4 and conveyance of recording paper 19. Therotational distance of the photosensitive body 4 for each line and thedistance through which the recording paper is fed for each line are thesame for all the lines while the time interval during which thephotosensitive body 4 is at rest and the time interval during which therecording paper is at rest vary from line to line and as a result therotational speed of the photosensitive body 4 and the conveyance speedof the recording paper 19 vary from line to line.

Assume that such control proceeds and the position on the photosensitivebody corresponding to the first line rotates from the developingposition P₂ to the transfer position P₃. The distance P₂ P₃ from thedeveloping position P₂ to the transfer position P₃ on the photosensitivebody 4 is set equal to the distance P₁, from the initial standbyposition P₁ to the transfer position P₃ on the recording paper, so thatwhen the first line position on the photosensitive body 4 rotates totransfer position P₃, the leading end of the recording paper has arrivedat the transfer position P₃. The time required for the photosensitivebody 4 to rotate through the distance P₂ P₃ varies in accordance withthe length of the image data, and is determined by counting EOL signals.

Thus the controller 40 counts EOL signals and starts the followingtransfer operation if the count has reached a predetermined valuecorresponding to the distance P₂ P₃ or P₁ P₃.

In the transfer process, the controller 40 inputs to the switch 21 asignal TS which becomes "1" synchronously with a fall of the MS signaland turns on the switch 21 at the same time of the pulse motor 16 beingstopped (FIG. 3(f)). Thus, as shown in FIG. 5(c), the recording paper 19is positively charged, the negatively charged toner is moved away fromthe photosensitive body 4 and transferred to the recording paper 19.

Since such operation is performed according to this particularembodiment, the recording speed in the subscanning direction, namely,the start timing of the exposure and development, the rotational speedof the photosensitive body 4 and the conveyance speed of a paper sheet19, may be altered in accordance with the time when image data for eachline is received. In this apparatus, exposure and development areperformed simultaneously, so that electrostatic charges in thephotosemiconductor layer 1 will not invite dark attenuation, a uniformlatent image is formed with a uniform image quality. Thus the apparatusis preferable as the recording device for a facsimile device.

According to this invention, the above embodiment may be modified in anappropriate manner. For example, all the voltages applied in theparticular embodiment may be inverted in polarity. While in theembodiment the transparent conductive layer 2 and the photosemiconductorlayer 1 are provided in this order on the transparent support 3 to formthe photosensitive body 4, an insulating layer may be provided on thephotosemiconductor layer 1 in which case the permittivity of thematerial between the photosensitive body 4 and the sleeve 10 and that ofthe material between the photosensitive body 4 and the transfer unit 20are increased to thereby increase the quantity of charges forming a unitvoltage, which means an effective use of the applied voltage.

While in the particular embodiment the permanent magnet shaft 9 of themagnetic brush developing unit 8 is fixed and the sleeve 10 is rotated,the invention is not limited to this particular structure. The sleeve 10may be fixed and the magnet shaft 9 may be rotated. Alternatively, thesleeve 10 and the magnet shaft may be rotated together.

While in the particular embodiment the toner 36 is shown as beingcomposed of a bi-ingredient one comprising carrier and toner powders,the invention is not limited to it and one-ingredient toner may be used.

The transfer unit may be composed of a roller which pushes the recordingpaper 19 against the photosensitive body 4 instead of the transfer unit20 of the embodiment. In this case, the toner image is more easilytransferred to the recording paper by the pressure force of the roller.

While in the particular embodiment the magnetic brush developing unit 8and the photosensitive body 4 are shown as being rotated in the oppositedirections a and b, the invention is not limited to it. Thephotosensitive body 4 and the developing unit 8 may be rotated in thesame directions.

While in the particular embodiment the photosensitive body 4 is shown asbeing drum-like, the invention is not limited to it. For example, it isonly required to have a laminated structure, as shown in FIG. 4, i.e.,for example, it may have a flat-plate photosensitive structure.

What is claimed is:
 1. An electrophotographic recording apparatus for afacsimile device comprising:a photosensitive body including atransparent conductive layer and a photosemiconductor layer layered inthis order on a transparent support; exposure means having a pluralityof light emitting elements disposed in a row and positioned on thetransparent support side of the photosensitive body for converting inputimage data for one line to an optical signal, irradiating thetransparent support of the photosensitive body with the converted lightsignal to form on the photosemiconductor an electrostatic latent imagecorresponding to the image data; development means disposed on theopposite side of the photosensitive body from the exposure means fordepositing toner having a polarity opposite to that of the electrostaticlatent image on the latent image in the photosemiconductor layer byapplication of a predetermined bias voltage to a developing electrode;transfer means for transferring the toner deposited on thephotosemiconductor layer to a recording medium; means for conveying therecording medium between the transfer means and the photosemiconductorlayer; means for rotating the photosensitive body; and control means foroperating the exposure means, the development means, the conveying meansand the rotating means synchronously with the receipt timing of receivedimage data for each line and synchronizing the light irradiation timingof the exposure means for each line, the timing of application of a biasvoltage in the development means for each line, the start timing of theconveyance of the recording medium for each line and the start timing ofthe rotation of the photosensitive body for each line with the receipttiming of the received image data for each line.
 2. Anelectrophotographic recording apparatus for a facsimile device accordingto claim 1, wherein the control means includes means for detecting anEOL signal representing the end of a line contained in the received dataand forming a main scanning line synchronizing signal on the basis ofthe EOL signal for synchronizing purposes.
 3. An electrophotographicrecording apparatus for a facsimile device according to claim 2, whereinthe control means performs light irradiation by the exposure means andapplication of the bias voltage to the development means substantiallysimultaneously with a rise of the main scanning line synchronizingsignal and rotates the photosensitive body substantially simultaneouslywith stoppage of application of the bias voltage.
 4. Anelectrophotographic recording apparatus for a facsimile device accordingto claim 1, wherein the recording medium conveying means and thephotosensitive body rotating means are actuated by the same drivesource.
 5. An electrophotographing recording apparatus for a facsimiledevice according to claim 1, wherein the exposure means includes:anarray of light emitting elements for one line disposed in a row; and anarray of self-collecting lenses for guiding the light from the array oflight emitting elements to the transparent support of the photosensitivebody.
 6. An electrophotographic recording apparatus for a facsimiledevice according to claim 2, wherein the development means includes:apermanent magnet shaft, a sleeve disposed so as to surround the magnetshaft, a power source for applying a predetermined bias voltage to thesleeve, a switch for selectively connecting the power source to thesleeve and a magnetic brush developing unit for drawing tonermagnetically onto the outer surface of the sleeve.
 7. Anelectrophotographic recording apparatus for a facsimile device accordingto claim 6, wherein the toner includes bi-ingredient toner of carrierand toner powers.
 8. An electrophotographic recording apparatus for afacsimile device comprising:a photosensitive body including atransparent conductive layer and a photosemiconductor layer layered inthis order on a transparent support; exposure means having a pluralityof light emitting elements disposed in a row and positioned on thetransparent support side of the photosensitive body for converting inputimage data for one line to an optical signal, irradiating thetransparent support of the photosensitive body with the converted lightsignal to form on the photosemiconductor an electrostatic latent imagecorresponding to the image data; development means disposed on theopposite side of the photosensitive body from the exposure means fordepositing toner having a polarity opposite to that of the electrostaticlatent image on the latent image in the photosemiconductor layer byapplication of a predetermined bias voltage to a developing electrode;transfer means for transferring the toner deposited on thephotosemiconductor layer to a recording medium; means for conveying therecording medium between the transfer means and the photosemiconductorlayer; means for rotating the photosensitive body; and control means foroperating the exposure means, the development means, the transfer means,the conveying means and the rotating means synchronously with thereceipt timing of received image data for each line and synchronizingthe light irradiation timing of the exposure means for each line, thetiming of application of a bias voltage for each line in the developmentmeans, the operation timing of the transfer means for each line, thestart timing of the conveyance of the recording medium for each line andthe start timing of the rotation of the photosensitive body for eachline with the receipt timing of the received image data for each line.9. An electrophotographic recording apparatus for a facsimile deviceaccording to claim 8, wherein the transfer means includes a dischargewire, a shield electrode surrounding the discharge wire, a power sourcefor applying a voltage to the shield electrode and a switch forselectively turning on the power source.
 10. An electrophotographicrecording apparatus according to claim 8, wherein the control meansstarts the operation of the transfer means a predetermined time afterthe exposure and development start.
 11. An electrophotographic recordingapparatus for a facsimile device according to claim 8, wherein thecontrol means includes means for detecting an EOL signal representingthe end of a line contained in the received data and forming a mainscanning line synchronizing signal on the basis of the EOL signal forsynchronizing purposes.
 12. An electrophotographic recording apparatusfor a facsimile device according to claim 11, wherein the control meansperforms light irradiation by the exposure means and application of thebias voltage to the development means substantially simultaneously witha rise of the main scanning line synchronizing signal and rotates thephotosensitive body substantially simultaneously with stoppage ofapplication of the bias voltage.
 13. An electrophotographic recordingapparatus for a facsimile device according to claim 8, wherein therecording medium conveying means and the photosensitive body rotatingmeans are actuated by the same drive source.
 14. An electrophotographingrecording apparatus for a facsimile device according to claim 8, whereinthe exposure means includes:an array of light emitting elements for oneline disposed in a row; and an array of self-collecting lenses forguiding the light from the array of light emitting elements to thetransparent support of the photosensitive body.
 15. Anelectrophotographic recording apparatus for a facsimile device accordingto claim 8, wherein the development means includes:a permanent magnetshaft, a sleeve disposed so as to surround the magnet shaft, a powersource for applying a predetermined bias voltage to the sleeve, a switchfor selectively connecting the power source to the sleeve and a magneticbrush developing unit for drawing toner magnetically onto the outersurface of the sleeve.
 16. An electrophotographic recording apparatusfor a facsimile device according to claim 15, wherein the toner includesbi-ingredient toner of carrier and toner powers.